(Revised Abstract) DESCRIPTION (provided by applicant): The Hybridoma Facility has provided Wistar investigators with murine monoclonal antibodies (MAbs) to a variety of novel tumor-associated antigens since 1985. MAbs produced by the facility have been successfully used in detecting tumor-associated antigens in patients' sera, for radiolocalizing tumors in patients, immunohistological diagnosis, and therapy of tumors. Murine MAbs continue to be a primary tool for tumor antigen characterization, detection, and purification. With advances in molecular cloning and generation of protein antigens in bacteria or by recombinant viruses, specific MAbs against a variety of novel antigens can be produced which were nearly impossible to obtain previously. The Hybridoma Facility continues to be an important asset for the majority of researchers at Wistar. The Scientific Director of the Hybridoma Facility, Dr. Andrew Caton, is an expert in MAb production and uses them extensively in his research. The capabilities of the facility include: Consultation with investigators to develop effective strategies for generating MAbs; Performance of immunization, bleeding, fusion and screening of hybridomas; Expansion of either new or existing hybridoma cell lines in vitro; Provision of either culture supernatant or purified antibody; Maintenance of a repository of hybridoma cell lines; and Production of antibodies ex vivo with a miniPerm bioreactor. In recent years, the facility has emphasized the use of fusion proteins (such as glutathione-Stransferase fusion proteins) to produce MAbs directed toward a variety of molecules associated with gene transcription, DNA repair, and cell division. In the future it is anticipated that the use of fusion proteins will facilitate the generation of MAbs directed to antigens that are identified through genomic array and proteomic screening of tumor cells.